Collar for drill steels



June 4, 1957 c. E. SEARS COLLAR FOR DRILL STEELS Filed July 9, 1954INVENTOR CLARENCE E. SEARS HIDS ATTORN-EY United States Patent 2,794,661COLLAR FOR DRILL STEELS Clarence E. Sears, Sherbrooke, Quebec, Canada,assignor to Ingersoli-Rand Company, New York, N. 1., a corporation ofNew Jersey Application July 9, 1954, Serial No. 442,357

3 Claims. (Cl. 287-85) This invention relates to drill steels, and moreparticularly to a collar that is readily attachable to and detachablefrom a drill steel.

Drill steels of the type to which the present invention pertains areused in rock drills having retaining devices as adjuncts to cooperatewith the collar for preventing ejection of the steel from the rockdrill. Heretofore, it has been customary to form collars on drill steelsby upsetting a portion thereof at a point chosen as the juncture of thebody portion of the steel and its shank. This operation, as may bereadily appreciated, requires both a considerable degree of skill andcostly machinery for carrying it out. In many instances, moreover, theforging operation develops defects which, when sub jected to the heavystresses of drilling, cause breakage of the drill steel in the area ofthe collar.

It is accordingly an object of this invention to obviate the need ofdisturbing the initial form of a drill steel requiring a collar.

Another object is to enable a drill steel to be expeditiously equippedwith a collar without the need of special skill or costly machinery.

Other objects will be in part obvious and in part pointed outhereinafter.

In the drawings accompanying this specification and in which similarreference numerals refer to similar parts,

Figure 1 is a side elevation of the front end portion of a rock drilland a drill steel therein, the latter being equipped with a collarconstructed in accordance with the practice of the invention,

Fig. 2 is an elevation, partly in section, of a drill steel and acollar, the parts of the latter being shown in position preparatory tothe final step of securing them to the drill steel,

Fig. 3 is a view similar to Fig. 2 showing the parts of the collar inthe positions which they occupy when firmly attached to the drill steel,and

Fig. 4 is a transverse view taken through Fig. 3 on the line 4-4.

Referring to the drawings, and at first more particularly to Figure 1,2t) designates the front end portion of a rock drill, 21 a drill steelactuated by the rock drill and 22 a retainer for preventing ejection ofthe drill steel from the rock drill.

The casing of the rock drill is provided, as is customary, withtrunnions 23 to support the retainer 22, and the yoke 24 of the retainerpartly encircles the drill steel 21 at a point a sufiicient distanceforwardly of the collar 25 to normally avoid contact between the two.

The collar 25 comprises an elongated member 26 which is preferably inthe form of a sleeve that is shaped internally to conform with thecontour of the drill steel 21. It is constructed of elastic material, asfor example rubber or neoprene which is readily deformable and may,therefore, be constricted and pressed into firm gripping engagement withthe drill steel.

mflwc The means serving to thus constrict the member 26 comprises a pairof easing parts 28 and 29 that fully encase the said member and a nut 30for drawing and securing the casing parts together. Each casing part hasa wall or shoulder 31 at its outer end to abut the adjacent ends of themember 26 and in said Walls are apertures 32 for the accommodation ofthe drill steel 21. The apertures 32 are of the same cross sectionalshape as the drill steel and preferably have a sufliciently close fitthereon to prevent the extrusion of the ends of the member at thesepoints.

In order to assure the compactness of the member 26 essential topreclude shifting thereof relativelyto the drill steel said member isinitially of somewhat greater length than the space it occupies in theoperative pos'itions of the parts. The portion 33 of the member 26.

encased by the part 28, as well as the part 28 itself,

is of frustoconical shape to permit of the free adjustment of all areasof the member 26 when subjected to the pressure of the casing. The innersurface 34 of the casing part 29, on the other hand, is of cylindricalshape as is also the portion 35 of the member 26 lying therein.

Preferably, the parts 28 and 29 have portions in telescopic engagementwith each other, the casing part 28 having an annular extension 36 thatextends into the part 29. The external surface 37 of the extension 36 isof cylindrical shape for sliding engagement with the inner surface ofthe part 29, and the free end of the annular extension 36 is in the formof a sharp edge 38 that may readily slide along the surface 34 withoutsnagging on the comparatively soft material of the member 26 when thecasing parts are being drawn together.

The nut 36 which serves to impart such movement to the casing parts isthreadedly connected to the part 29 and has an introverted flange 39 atone end to overlie and engage an external flange 40 on an intermediateportion of the part 28. The opening 41 defined by the flange 39 is of asize to readily pass all portions of the part 28 other than the flange40 and the nut 30 has suitable flatted surfaces 42 for the accommodationof a wrench whereby it may be manipulated.

In practice, whenever it is intended to attach a collar to a drill steelthe member 26 is first disposed in a desired position on the drillsteel. The casing parts 28 and 29 are next disposed about the member 26and the nut 30 is manipulated to draw them together. Such movement ofthe casing parts will have the effect of constricting the member 26 andforcing it into firm gripping engagement with the drill steel where itwill remain unaffected by any jars imparted thereto when projectedagainst the yoke 24 of the steel retainer or when thrust against thefront end of the rock drill.

In the event that the drill steel becomes broken, or otherwise useless,the parts constituting the collar may be conveniently removed for re-useand without the need of tools other than those which are normallyavailable at the drilling site.

I claim:

1. A detachable collar for a drill steel comprising an innercompressible member having a longitudinal hole of uniform sectionsubstantially conforming to the configuration of the steel, said memberhaving an outer surface continuously tapered for the greater part of itslength and substantially cylindrical toward one end, a first casingmember tapered inside to receive the tapered part of said compressiblemember, and a second casing member cylindrical to receive thecylindrical end of said compressible member, and means to draw saidcasing members together in telescoping relation to each other forcontracting the compressible member onto the steel.

2. A detachable collar for a drill steel comprising an innercompressible member having a longitudinal hole of uniform sectionsubstantially conforming to the configuration of the steel, said memberhaving an outer surface continuously tapered for the greater part of itslength and substantially cylindrical toward one end, a first casingmember tapered inside to receive the taperedpart of said compressiblemember, and a second casing member cylindrical to receive thecylindrical end of said. compressible member, and means to draw saidcasing members together in telescoping relation to each other forcontracting the compressible member onto the steel, each of said casingmembers having an abutment end face closely fitting the steel and heldagainst rotation thereby.

3. A detachable collar for a drill steel comprising an innercompressible member having a longitudinal hole of uniform sectionsubstantially conforming to the configuration of the steel, said memberhaving anouter surface continuously tapered for the greater part of itslength and substantially cylindrical toward one end,

References Cited in the file of this patent UNlTED STATES PATENTS2,431,120 Howe Nov. 18, 1947 2,562,359 Iredell July 31, 1951 2,721,084Weiss Oct. 18, 1955

